Not a breath of air was astir. The night came on still as the realms
of solitude. Only the low chatter of the men, the occasional stamp of
iron-shod hoof or the munching jaws of the tired steeds broke in upon
the perfect silence. From their covert in the westward slope of the
Christobal the two sentries of the little command looked out upon a
lifeless world. Beneath them, whiffing their pipes after their frugal
supper, the troopers were chatting in low tone, some of them already
spreading their blankets among the shelving rocks. The embers from the
cook fire glowed a deeper red as the darkness gathered in the pass,
and every man seemed to start as though stung with sudden spur when
sharp, quick, and imperative there came the cry from the lips of the
farther sentry,--

"Fire, sir,--out to the west!"

In an instant Lieutenant Drummond had leaped down the rocky cañon and,
field-glass in hand, was standing by the sentry's side. No need to
question "Where away?" Far out across the intervening plain a column
of flame was darting upward, gaining force and volume with every
moment. The lieutenant never even paused to raise the glass to his
eyes. No magnifying power was needed to see the distant pyre; no
prolonged search to tell him what was meant. The troopers who had
sprung to their feet and were already eagerly following turned short
in their tracks at his first word.

"Saddle up, men. It's the beacon at Signal Peak."

Then came a scene of bustle. No words were spoken; no further orders
given. With the skill of long practice the men gathered their few
belongings, shook out the dingy horse-blankets and then, carefully